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The prevalence of mupirocin resistant MRSA of long-term care facilities

Abstract number: 1134_02_192

Yoo J.I., Shin E.S., Cha J.O., Lee J.K., Eun S.H., Kim B.S., Lee Y.S.

Objectives:

The long-term care facilities (LTCFs) patients are those with serious underlying disease, poor functional status, wounds such as pressure sores, invasive devices of urinary catheters. There is increasing concern about the emergence of resistance to antimicrobial agents including methicillin resistant S. aureus in LTCFs and mupirocin has been used in LTCFs to prevent the occurrence and spread of MRSA. But the prevalence of mupirocin resistant MRSA in LTCFs has not been known yet in Korea. In this study, we investigated the prevalence of mupirocin resistant MRSA from LTCFs and their molecular epidemiological analysis.

Methods:

749 specimens were obtained from 632 patients of 8 LTCFs from July to August 2002. Specimens were cultered on staphylococcal medium and species were identified by PCR and biochemical test. Antimicrobial susceptibility tests to 12 antibiotics were performed by disc diffusion method, MICs of oxacillin, mupirocin were confirmed by agar dilution method and E-test method. Mupirocin resistant isolates were divided into low level mupirocin resistant (MuL) and high level mupirocin resistant (MuH) by according to criteria <= 256 mg/ml and >= 512 mg / ml, respectively. PFGE and RFLP typing were performed for molecular epidemiological analysis of mupirocin resistant isolates.

Results:

365 S. aureus (48.7%) were isolated from the LTCFs specimens and 259 isolates (70.9%) were identified resistant to oxacillin. mecA gene was detected in all tested 259 MRSA isolates with MICs of 16 - >128 mg / mL. The mupirocin resistance was 19.3% range from 1.3% to 72.4% of MRSA depending on LTCFs. In one LTCF, 20 out of 39 MRSA isolates were MuH including 15 isolates showing the same PFGE pattern. In the other one LTCF, 19 out of 29 MRSA isolates were MuL with the same PFGE pattern in 17 isolates. Among 26 MuH MRSA detected in 4 LTCFs of 8 LTCFs, the most predominant mupA RFLP type was 4.2 kb EcoRI-8 kb HindIII-2.1 kb ClaI (22 isolates) hybridizing fragments.

Conclusion:

Mupirocin resistant MRSA in LTCFs was 19.3%, range from 1.3 to 72.4%. And it is supposed that there was mupirocin resistant MRSA outbreak in two LTCFs. This suggests that the mupirocin resistant MRSA is spread in LTCFs and need the prevention strategy.

Session Details

Date: 01/08/2007
Time: 00:00-00:00
Session name: XXIst ISTH Congress
Subject:
Location: Oxford, UK
Presentation type:
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